Dynamic Boolean Searches AND, OR,

Hi, I am looking for an easy and efficiant way to add a boolean search function to an already existing search i have using ASP pages and MSSQL 2000 SPROCS.

Currently I have some code such as:

CREATE PROCEDURE sp_name

@var1 int = NULL,
@var2 varchar(50) = NULL

AS

SELECT blah, blah, blah
FROM sometable INNER JOIN anothertable ON anID = anID
WHERE (table1.column2 = COALESCE(@var1,table1.column2) AND table2.column4 = COALESCE(@var2,table2.column4))


and this works like a charm, if i pass a value into @var1 or @var 2 it gives back results where those crietera match, or if I pass no values in it returns all records.... anyways, you get the idea...

Now I would like to add the ability to introduce a 3rd variable, and have it run a boolean search on a varchar(2500) column. This column is a description field for an image so I would like to be able to search the descriptions by passing in something like 'car OR bike AND travel' and return all the records that have the words 'car' or 'bike' and 'travel' somewhere in the description field.

How can i do this? I am using SQL Server Standard Edition so I don't believe I have full text search functions available, (not sure if that would even help).

Thanks all for your support and guidance!

P.S. i would also like to maintain the functinality so that if all the @var# are blank it still returns all records.